No. Frequency Generator 1940 is a one-time $0.99 purchase — no ads, no in-app purchases, no subscription, ever.
What frequency range does it cover?
20 Hz to 20 kHz, the full range of human hearing, on a logarithmic knob for fine control at low frequencies. You can also dial in an exact musical note (C0 through B7) instead of a raw frequency.
What waveforms are available?
Sine, square, triangle, and sawtooth.
What's the Sweep button do?
Continuously sweeps the frequency across the full 20 Hz–20 kHz range — useful for a quick hearing check or testing speaker response.
I don't hear anything
Check your device isn't in silent/mute mode and the volume knob in the app isn't turned all the way down. Very low (sub-40 Hz) and very high (above ~17 kHz) tones may be inaudible depending on your speaker and hearing range — that's expected, not a bug.